<?php

if (! defined('BASEPATH'))
    exit('No direct script access allowed');

/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 5.1.6 or newer
 *
 * @package CodeIgniter
 * @author ExpressionEngine Dev Team
 * @copyright Copyright (c) 2008 - 2011, EllisLab, Inc.
 * @license http://codeigniter.com/user_guide/license.html
 * @link http://codeigniter.com
 * @since Version 1.0
 * @filesource
 *
 */
    
// ------------------------------------------------------------------------

/**
 * CodeIgniter Benchmark Class
 *
 * This class enables you to mark points and calculate the time difference
 * between them. Memory consumption can also be displayed.
 *
 * @package CodeIgniter
 * @subpackage Libraries
 * @category Libraries
 * @author ExpressionEngine Dev Team
 * @link http://codeigniter.com/user_guide/libraries/benchmark.html
 */
class CI_Benchmark
{

    /**
     * List of all benchmark markers and when they were added
     *
     * @var array
     */
    var $marker = array();
    
    // --------------------------------------------------------------------
    
    /**
     * Set a benchmark marker
     *
     * Multiple calls to this function can be made so that several
     * execution points can be timed
     *
     * @access public
     * @param string $name
     *            the marker
     * @return void
     */
    function mark ($name)
    {
        $this->marker[$name] = microtime();
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Calculates the time difference between two marked points.
     *
     * If the first parameter is empty this function instead returns the
     * {elapsed_time} pseudo-variable. This permits the full system
     * execution time to be shown in a template. The output class will
     * swap the real value for this variable.
     *
     * @access public
     * @param
     *            string a particular marked point
     * @param
     *            string a particular marked point
     * @param
     *            integer the number of decimal places
     * @return mixed
     */
    function elapsed_time ($point1 = '', $point2 = '', $decimals = 4)
    {
        if ($point1 == '') {
            return '{elapsed_time}';
        }
        
        if (! isset($this->marker[$point1])) {
            return '';
        }
        
        if (! isset($this->marker[$point2])) {
            $this->marker[$point2] = microtime();
        }
        
        list ($sm, $ss) = explode(' ', $this->marker[$point1]);
        list ($em, $es) = explode(' ', $this->marker[$point2]);
        
        return number_format(($em + $es) - ($sm + $ss), $decimals);
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Memory Usage
     *
     * This function returns the {memory_usage} pseudo-variable.
     * This permits it to be put it anywhere in a template
     * without the memory being calculated until the end.
     * The output class will swap the real value for this variable.
     *
     * @access public
     * @return string
     */
    function memory_usage ()
    {
        return '{memory_usage}';
    }
}

// END CI_Benchmark class

/* End of file Benchmark.php */
/* Location: ./system/core/Benchmark.php */